Medical imaging apparatuses are used to obtain an image of an internal structure of an object. Medical imaging apparatuses that are non-invasive testing apparatuses capture images and provide a processed image to a user including processed structural details, internal tissues, and the flow of fluids in a human body. The user, who is, for example, a medical doctor, may diagnose a health state and a disease of a patient by using a medical image output from a medical image processing apparatus.
A computed tomography (CT) apparatus is a typical apparatus among apparatuses for capturing an image of an object by projecting X-rays to a patient.
Among medical image processing apparatuses, the CT apparatus may provide a cross-sectional image of an object that may show an internal structure (e.g., organs such as kidneys or lungs) of the object without overlapping elements in the internal structure, compared to a general X-ray apparatus. Therefore, the tomography apparatus is widely used for accurate diagnosis of diseases. Hereinafter, a medical image obtained by the apparatus is referred to as a tomography image.
To obtain a tomography image, a tomography scan is performed on the object by using a tomography apparatus, and thus raw data is obtained. Then, the tomography image is reconstructed by using the obtained raw data. The raw data may be projection data, which is obtained by projecting X-rays to the object, or a sinogram that is a group of pieces of the projection data.
Due to movement of a tomography apparatus or an object to be scanned or due to performance of the tomography apparatus, blurring artifacts may occur when reconstructing a tomography image. For example, the tomography apparatus itself may undergo shaking during an operation, resulting in blurring artifacts in an image.
When blurring artifacts occurs, an outermost edge of the object may be unclear. Also, an inner edge of the CT image may be blurred due to blurring artifacts.
In addition, if an object to be scanned moves, movement of the object may also occur within one period, causing motion artifacts when reconstructing a CT image.
As described above, blurring artifacts and motion artifacts in a CT image may decrease the quality of the CT image, and thus hinder the ability of the user, such as a medical doctor, to accurately read the CT image and diagnose diseases.
Therefore, in tomography, blurring artifacts and motion artifacts of a tomography image need to be minimized.